Improvement in core-retainer for tubular rock-drills



m.) c. L sTEv-Efism Improvement in Core Retainer for Tuhziar Rock Drills. No 121,821 Patented D'ec.'12,1871.

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CHARLES J. STEVENSON, OF HAZEL GREEN, WISCONSIN, ASSIGNOR TO HIMSELF AND MARTIN H. DUGKWORTH, OF NEW YORK CITY.

IMPROVEMENT IN CORE-RETAINER FOR TUBULAR ROCK-DRILLS.

Specification forming part of Letters Patent No. 121,821, dated December 12, 1871.

To all whom "it may concern:

Be it known that I, OHARLEs J. STEVENSON, of Hazel Green, in the county of Grant and State of Wisconsin, have invented an Improved Gore- Retainer for Tubular Rock-Drill; and I do hereby declare that thefollowingis afull, clear, and exact description thereof, which will enable others skilled in the art to make and use the same, reference being had to the accompanying drawing forming part of this specification.

Figure 1 represents a longitudinal section of a drill-tube taken on the plane of the line 0 c, Fig. 2. Fig. 2 is a transverse section of the same on the line k is, Fig. 1.

Similar letters of reference indicate corresponding parts.

This invention has for its object to provide within the tube of a rock-drill a reliable detainer for any broken sections of core, and one that will not injure soft matter passing through the tube. The invention consists in the application of sprin gjaws within the tubular shank of the drill in place of the adjustable wedges heretofore in use. The springs are by the entering cores crowded outwardly, allowing them to pass, but spring against the ends of entered sections when dropping down.

In the rock-drills which are now in use there are wedges for arresting the core and preventing it from falling out when the motion is reversed or arrested. These wedges, however, are of such nature as to crumble soft material and make the obtaining of a perfect core almost impossible. In boring for veins of valuable minerals it is necessary to obtain a perfect core in order to ascertain the quality and kind of material, but also the distance from and between certain veins. Therefore the preservation of the core is an absolute requisite.

A in the drawing represents the drill-tube. WVithin it, a short distance above the boring-end, are two or more jaws, B B, which are forced inwardly by means of springs a a. The jaws are set into recesses that are cut into the inner side of the tube, hooking, by preference, over shoulders 1) formed at the lower ends of the recesses.

I apply the jaws at the upper part of a section of tubing and confine them under another section screwed upon the first, as in Fig. 1, an inner lip, (1,011 the upper section confining the inward motion of the jaws. The core, while entering the tube A, can conveniently pass up therein, as the springs will yield and let it pass. The slight jarring motion of the tube will cause the core to break into sections of greater or less length. Whenever the motion is reversed or arrested the sections of core will be arrested by the springjaws, which catch under the end of the section directly above, as shown.

Having thus described my invention, I claim as new and desire to secure by Letters Patent The spring-jaws applied within a tubular rockdrill, substantially as and for the purposes herein shown and described.

CHARLES J. STEVENSON.

Witnesses:

H. L. MANN,

T. DOYLE. (124.) 

